Current transfer cases typically put the rear output in line with the transmission input and then offset the front output to one side of the engine or the other. That wasn’t always the case, though. The arrows and lines on the Dana Spicer 20 (left) and Dana Spicer 18 show a couple of different power-flow paths. These gear-driven cases were used in Jeeps from the WWII era up through the ’70s. The 20s were also used on first-generation Broncos.